Certain applications of hydraulic systems involve the control of two drive units which, with separate movements, drive a working unit. This may include a hydraulic motor which works under load which varies greatly over time, which has hitherto involved certain problems. A major problem is the risk of interference between the functions of the two drive units. The inertia in a conventional hydraulic system can also mean that the hydraulic fluid flow is not sufficient for supplying the motor. Another critical situation with a risk of cavitation damage is when the motor is actuated into stop position.
A computer-controlled system for controlling the feed of a sawing unit on the basis of a number of control parameters is known from WO 01/84910.